Collocating means for measuring radii



Dec. 20, 1955 R. w. woNDx-:Rs

COLLOCATING MEANS FOR MEASURING RADII Filed April l5l 1950 United States Patent O --coLLocA-'HNG ron MEASURING RADII "My invention relateslto the 'art of taking radial 'measurements on pieces `being formed on machines havlng a true center axis; Specifically I have invented a method and a means for making these measurements with standard instruments 'by supplying a tool 'or holder for the measuring 'instrument that'supports it with one end of its measuring yelement at the true center axis of the machine and the Y 'other lat a *point on a radially `extending line from said Ytrue center axis.

nAs typical of the problem for which I offer Va unique solution, let us consider the measurement Vof the depth of a fet `to vform -a tooth on a female,l gear trimming die for 'a gear Vhavingtan odd ,number'ofteeth 4In the makingof 'snh a gear die, the 'stock is lirst bored "to the size of the ge'r body at vthe base of lthe teeth. `It is then necessary to make a series of cuts extending radially and generally inthe form of `a truncated acute `isosc'ele's triangle at any given plane in the height of the cut a'sillustrated in Fig. 3.

These cuts are spaced evenly around the original boring 4-to an equal depth. vBecause 'they are kodd in numb'er, however, Vnortwo of them will bejdiametrically 'opto each other. The machine yon which the vcutting is doriemay be avery goodone Vand the Aca rlibrations on the controls of the machine indicating the depth of lcut taken may be accurate withinthe allowabletolerances.called for by the Work. It is vusually considered desirable, nevertheless, to check ihe 'work with struments. micrometer. Until now V the methodfof making these measurements has been relatively crude and placed on the operator an extraordinary demand Afor skill kand care.

precision measuring inv1n this caseitwould `be by using-'an inside Sinccthere was no known goodmethod 'of measuring the l radii directly, the procedure was to measure thejdiarneter which,fof course, was not entirely accurate since there-Was 11d-guarantee hat thafiiamster measurement, even firearre'ct, extended an equal ,distance to either side of the center. In addition it'wa's necessary to make an arithmetical calculation `since .the larger diameter .could not Ebe measured directly. Because no two teeth cuts were exactly opposite each other, a measurement across the gear was taken from the side of the gear body cut, i. e., the irst boring, to the cut made for a tooth. It was then necessary to add the depth of a second tooth cut to this direct measurement to arrive at a diameter figure. This extra arithmetical step provided another opportunity for error. In combination with the inherent error of attempting to measure radii by checking diameter and halving the figure so obtained, the extra chance for error in adding the amount of a hypothetical tooth cut made this old system somewhat unreliable especially in view of the precision normally anticipated in performing this kind of work. The example here described in some detail may be multiplied many times over on all kinds of circular work on machines having what is known as a true center axis such as lathes, drill presses, vertical Shapers, and many others. Also it will be seen that my method and means for measuring radii simplifies the making of other radii measurements as well as solving the particularly vexing problem presented here.

In View of the foregoing discussion it is the principal ob- 'ject of my invention to provide a method of taking direct measurements of radii on work being processed on machines having a true center axis and well. It is a further object of my invention to provide a means for executing my method of taking radii measurements with standard :precision instruments on Work being processed on machines equipped with a true center well on the work-holding portion of the machine.

It is a further object of my invention to provide a method for making direct measurements of radii on work 'being processed on machines having a true center axis that requires a measuring instrument holder that is economical of manufacture and durable in use.

These and other objects will be apparent to those skilled 'in the art.

My invention consists in the methodand in the means having its parts arranged and constructed to achieve my invention as hereinafter more fully set forth, pointed out in my claims, and illustrated in the accompanying drawings, in which:

Fig. l is a front View of my measuring instrument holder with broken lines showing a fragmentof a work supporting surface of a machine having a true center Well and showing how the holder iits down in the well.

Fig. 2 is a side View of my instrument holder with broken lines showing -a fragment of a work holding table as in Fig. l and also showing the screw means for securing the holding block to the reference face. l

K Fig. 3 is atop view of my device to illustrate the method of using it to make radii measurements, with broken lines showing an inside micrometer in two positions and a 'fragment of awork holding table.

Referring to the drawings the numeral 10 designates the straight sided stub shaft that slideably lits a true center well 11 of the work holding member 12 of machinetool. vA shoulder designated 13 is machined -just above the shaft. -At one side the`tool extends straight upwardly to form the reference block 14 presenting a plane surface 15 that is on the center line of the stub shaft at its base and exktends upwardly so that a continuation of the center line of the stub shaft would lie within plane surface 15. The fshoulder 13 at the side opposite to that of reference block is cut away in the form of a shelf 16 to expose plane surface 15. This shelf is preferably at right angles to sur- .face 15 so that lthe holding block 17 may be more easily {itted to `surface 15. Holding block 17 is secured to surface "15 in any suitable manner and preferably detachably so secured as 'by screws 18 and 19 threading into appropriately 'threaded holes in block 14. Block 17 Vhas an appropriate aperture 20 machined in it. This hole or aper- -ture 20 is so arranged with respect to block 17 that its longitudinal axis is perpendicular to surface 15 and would intersect the center line of stub shaft 10. In Fig. 3 a female die 21 1s shown secured to the work holding member 12 of a machine tool and my invention mounted in the true center well thereof. An inside micrometer 22 is shown held in two different positions measuring radii directly to the tooth cuts 23 and 24 respectively which it will be noted are not directly across from each other and could not, therefore, be easily measured with any real accuracy by measuring a diameter. It will be noted that one end of the micrometer extends to the plane surface 15 so that it is at the exact center axis of the work table and, therefore, measures true radii. While I have shown my holder used with an inside micrometer, the measuring instrument could also be readily adapted to take outside measurements as well. The holding block 17 that slideably receives the measuring instrument 22 in aperture 20 3 is preferably blocks to permit my invention to be adapted to any standard measuring instrument. lt will be understood, of course, that any Vtyperof machine having a true center well is one with which my tool may be profitably used. ,It is also necessary to realize that while I have shown the holder in use to measure work accomplished, it may also be used to lay out work in the planning stage.

Some changes may be maderin therconstruction and arrangement of my method and means for measuring radii without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims, any Amodified forms of structure or use of mechanical equivalents which may be reasonably included within `their scope.

I claim: j Y

' 1. In combination with a machine having a true center well, a radii measuring reference point tool comprising; a member designed to slideably and rotatably t said true center well and having a plane surface one line of which coincides with a corresponding length of a straight extension of the longitudinal axis of said true center well, and a block having a hole therein secured to said plane surface so that the longitudinal axis of said hole is perpendicular to said plane surface and intersects a straight extension of the longitudinal axis of said true center well.

2. In a radii measuring center reference tool in combination with a machine having a true center axis, a rst block member presenting a plane surface, a means for supporting said block in reference to the true center of a machine so that a line of said plane surface coincides with a corresponding length of a straight extension of said true center axis, and a second block having a hole therein fixed in relation to said first block so that the longitudinal axis of said hole in said second block is perpendicular to said plane surface and intersectsV the line of said plane thatV may be arranged to coincide with a portion of a straight extension of the true center axis of a machine.

3. In a radii measuring reference point tool in combination used with a linear measuring instrument and a ma` chine having a true center axis, a block having a plane surface, a means for rotatably supporting said block so that a line of its plane surface coincides with a correspending length of a straight extension of said true center axis, and a means for holding the measuring portion of a linear measuring instrument perpendicular to said plane surface and touching the line of said plane surface that removable to permit the use of other holding y I y ,i 4 v chine and capable of receiving and holding a linear measuring instrument withuone end f its length mesucoincides with a portion of said extension of said true center axis.

4. In a radii measuring reference point tool in combination used with a linear measuring instrument and a machine having a true center axis, a block member capable of being detachably secured to a machine having a true center axis so that a straight continuation of the true center axis of the machine would lie within its bulk; said block having a plane bottomed well therein extending solely to said continuation of a true center axis of a maing portion abutting the plane bottom of said well and its length extending radially therefrom.

5. In combination with a machine having a true center well, a radii measuring reference point tool comprising; a member designed to slideablyiit said true center well and having a plane surfaceone line of which coincides with a corresponding length'of a straight extension of the longitudinal axis of said true center well, and a block having a hole therein detachably secured to said plane surface so that the longitudinal axis `of said holel is perpendicular to said plane surface and intersects a straight extension of the longitudinal axis ofsaid true center well.

6. In a radii measuring center reference tool in combination with a machine having a true center axis, a first block member presenting a plane surface, a means for supporting said block in reference to the truecenterA of a machine so that a line of said plane surface coincides with a corresponding length of a straight extension of said true center axis, and a second block having a hole therein detachably xed in relation to said rst block so that'the longitudinal axis of said hole in said second block is perpendicular to said plane surface and intersects the yline lof said plane that may be arranged to coincide with a portion of a straight extension of the true centeraxis of a machine. v V

7. In a radii measuring reference point tool in' combination with a machinehaving a true center well therein, ay reference point block having a vstub shaft formed thereon adapted to slidably and rotatably fit the .true center well of a machine; said referencepoint block having a reference point portion thereon coinciding with an extension of the longitudinal axis of the stub shaft of said referencepoint block, and a means secured to said reference point block for holdinga linear measuring device with one end of its measuring meanscoinciding with the reference point of said reference point block; whereby lineal radial measurements are made fromrthe true center axis of a machine to points surrounding the true .een- ,ter axis of a machine. Y

References in the file of this patent UNITED STATES PATENTS 451,053 Jackman Apr. 18, 672,213 Holcomb` Apr. 16, 1901 2,173,519 Jones Sept. 19, 1939 2,348,712 Dahlerup May 16, 1944 2,369,425 Becker Feb. 13, 1945 2,419,134 Hall Apr.'y 15, l1947 2,551,242 Burwinkle May 1,1951 2,621,416 Brenneke Dec. 16, 1952 yFOREIGN-,PKFENTS 13,703 1887 GreatV BritainV Oct. 10, 

